function dataUrlToBase64(str) {
  const array = str.split(',')
  return array[array.length - 1]
}

let index = 0
function getNewFileId() {
  return Date.now() + String(index++)
}

function biggerThan(v1, v2) {
  const v1Array = v1.split('.')
  const v2Array = v2.split('.')
  let update = false
  for (let index = 0; index < v2Array.length; index++) {
    const diff = v1Array[index] - v2Array[index]
    if (diff !== 0) {
      update = diff > 0
      break
    }
  }
  return update
}

export default function base64ToPath(base64) {
  return new Promise(function (resolve, reject) {
    if (typeof window === 'object' && 'document' in window) {
      base64 = base64.split(',')
      const type = base64[0].match(/:(.*?);/)[1]
      const str = atob(base64[1])
      let n = str.length
      const array = new Uint8Array(n)
      while (n--) {
        array[n] = str.charCodeAt(n)
      }
      return resolve((window.URL || window.webkitURL).createObjectURL(new Blob([array], { type: type })))
    }
    let extName = base64.split(',')[0].match(/data\:\S+\/(\S+);/)
    if (extName) {
      extName = extName[1]
    } else {
      reject(new Error('base64 error'))
    }
    const fileName = getNewFileId() + '.' + extName
    if (typeof plus === 'object') {
      const basePath = '_doc'
      const dirPath = 'uniapp_temp'
      const filePath = basePath + '/' + dirPath + '/' + fileName
      if (!biggerThan(plus.os.name === 'Android' ? '1.9.9.80627' : '1.9.9.80472', plus.runtime.innerVersion)) {
        plus.io.resolveLocalFileSystemURL(
          basePath,
          function (entry) {
            entry.getDirectory(
              dirPath,
              {
                create: true,
                exclusive: false,
              },
              function (entry) {
                entry.getFile(
                  fileName,
                  {
                    create: true,
                    exclusive: false,
                  },
                  function (entry) {
                    ;(entry as any).createWriter(function (writer) {
                      writer.onwrite = function () {
                        resolve(filePath)
                      }
                      writer.onerror = reject
                      writer.seek(0)
                      writer.writeAsBinary(dataUrlToBase64(base64))
                    }, reject)
                  },
                  reject
                )
              },
              reject
            )
          },
          reject
        )
        return
      }
      const bitmap = new (plus as any).nativeObj.Bitmap(fileName)
      bitmap.loadBase64Data(
        base64,
        function () {
          bitmap.save(
            filePath,
            {},
            function () {
              bitmap.clear()
              resolve(filePath)
            },
            function (error) {
              bitmap.clear()
              reject(error)
            }
          )
        },
        function (error) {
          bitmap.clear()
          reject(error)
        }
      )
      return
    }
    if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) {
      const filePath = wx.env.USER_DATA_PATH + '/' + fileName
      wx.getFileSystemManager().writeFile({
        filePath: filePath,
        data: dataUrlToBase64(base64),
        encoding: 'base64',
        success: function () {
          resolve(filePath)
        },
        fail: function (error) {
          reject(error)
        },
      })
      return
    }
    reject(new Error('not support'))
  })
}
